新型航空发动机空气冷却器流动传热性能试验

Flow and Heat Transfer Performance Test of a New Type Air Cooler for Aeroengine

空气冷却器是航空发动机中空气热量交换的重要场所,针对传统扰动结构强化换热不足问题,重点研究了空气冷却器中扰动结构的结构形貌特征与流动换热的关系。以三周期极小曲面结构为基础,设计制造了D型极小曲面扰动结构、P型极小曲面扰动结构和基于Sigmoid函数杂化方法的D-P型(P-D型)结构。并利用纳米CT重构出样品的3维数字特征,试验研究了不同结构来流速度与压降、换热性能和综合换热性能的关系。结果表明:D型极小曲面结构具有最优的压降、换热性能和综合换热性能:D-P型杂化极小曲面结构的阻力系数f最大,比D型结构的高56.81%;D型的平均努塞尔数Nu比P型的高18.49%,P-D和D-P杂化结构的换热性能比P型结构的有效提高;P-D型D-P型杂化结构的Nu分别比P型结构的高2%和8.27%。在4种结构中,D型结构的综合换热性能最优,分别比P型、P-D型、D-P型结构的高40.35%、57.2%、71.02%。

An air cooler is an important place for air heat exchange in aeroengine.In response to the problem of insufficient heat transfer enhancement by traditional disturbedstructures,this paper focuses on the relationship between the structure morphology characteristics of disturbance structures and the flow and heat transfer performances of the air cooler.Based on the triply periodic minimal surface structure,the D-type and P-type triply periodic minimal surface structure,and a Sigmoid function-based hybrid structure P-D type(D-P type)were designed and manufactured.The digital characteristics of the samples were reconstructed by nano-CT.For these structures,the relationships between the flow velocity and pressure drop,heat transfer performance,and overall heat transfer performance were experimentally studied.The results show that the D-type triply periodic minimal surface structure has the best pressure drop,heat transfer performance,and overall heat transfer performance.The D-P type hybrid triply periodic minimal surface structure has the largest drag coefficient(f),which is 56.81%higher than that of the D-type structure.The average Nusselt number(Nu)of the D-type is 18.49%higher than that of the P-type.The heat transfer performances of the P-D type and the D-P type hybrid structure are effectively improved compared to the P-type structure.The Nu of the P-D type and D-P type hybrid structures are 2%and 8.27%higher than that of the P-type structure,respectively.Among the four structures,the D-type structure has the best overall heat transfer performance,which is 40.35%,57.2%,and 71.02%higher than that of the P-type,P-D type,and D-P type respectively.